The earlier effective filing date of co-pending U.S. Provisional Application Ser. No. 60/678,625, entitled “Microtitre Plate With a Relieved Perimeter,” filed May 6, 2005, in the name of the inventors Richard P. Bunch, et al. is hereby claimed and the application is hereby incorporated by reference for all purposes as if expressly set forth herein verbatim.
1. Field of the Invention
The present invention pertains to microtitre plates.
2. Description of the Related Art
Many types of testing dispose samples in the wells of a microtitre plate. Sometimes the samples are disposed directly into the wells. Other times, sample holders are used to transfer samples into or out of the wells of the microtitre plates. In commercial applications, the volume of testing is important both for economies of scale and for quick turnaround. Accordingly, robotic equipment has been developed to automate the testing, which includes the handling of microtitre plates.
The industry has also developed standards defining the dimensions and design of microtitre plates to facilitate the standardization of the robotic handling and testing machines. For instance, the Society of Biological Screening (“SBS”) defines standards for microtitre plates having 96, 384, or 1,536 wells. Commercial pressures continue to push the design of the testing process, including the design of the handling equipment and microtitre plates, to increase the pace at which testing can be performed. However, these same commercial pressures also tend to constrain such improvements to be compatible with the installed base of the testing apparatus used by the industry.
One aspect of the testing process where these concerns intersect lies in the inability to access only a subset of the wells on the microtitre plate. For instance, the standards define a microtitre plate layout in which the wells are disposed in a two-dimensional array. The perimeter of the microtitre plate is thicker than the walls between the wells. Typically, the robotic handling machine will include a two-dimensional array of mandrels that engage a corresponding array of fluid dispensing tips disposed in a pattern matching that of the wells on the microtitre plate. The array of fluid dispensing tips is positioned over the microtitre plate and then lowered so that the tips are inserted into the wells.
This arrangement works quite well as long as the testing protocol calls for all of the wells on the microtitre plate to be treated both identically and contemporaneously. If for some reason only a subset of the wells on the microtitre plate are to be treated at some point, problems may arise. The thickened perimeter of the microtitre plate can prevent the array of fluid dispensing tips from simply being offset relative to the microtitre plate such that only a portion of the tips may be lowered into a subset of the wells to treat that subset. If this were attempted, the thickened perimeter would block the downward movement of the tips since they are spaced for the narrower width of the walls between the wells. Thus, testing protocols must either forego this strategy or employ longer, less efficient strategies to accomplish the same end.
The present invention is directed to resolving, or at least reducing, one or all of the problems mentioned above.